1. Field of the Invention
This invention relates to orthopedic appliances and in particular to deformable splints for application to the elbow, hand or knee of a human patient to achieve a gradual, controlled extension of the limb to which it is applied.
2. State of the Prior Art
Persons debilitated by old age or chronic illness, particularly those bound to a wheelchair or bedridden, develop a tendency to retract their limbs to a persistently contracted condition. The arm, leg and hand are all susceptible to this affliction.
An accepted treatment for this condition is for a physical therapist to exercise the affected limb by flexing the pertinent joint through the range of motion possible under the circumstances, and applying light force to extend the limb slightly beyond the existing range of motion. The exercised limb is then fixed at the maximum achieved extension by means of an orthosis, or splint, which bridges the joint being exercised and prevents its retraction. This procedure is repeated during successive therapy sessions, over a period of weeks, to achieve a progressive extension of the limb. The orthosis is adjusted following each session to prevent the limb from retracting beyond the maximum extension gained during the particular session.
The nearest pertinent prior art is believed to be described in U.S. Pat. No. 5,248,292 issued to Holland, which discloses a static orthosis for use similar to the orthosis of this invention. Briefly, the Holland orthosis consists of a deformable unitary body having two pads connected by a spine. The unitary body is made up of an aluminum endoskeleton which is deformable by means of sufficient manual force and retains a desired shape when so deformed. The endoskeleton is molded in a closed cell polyethylene foam matrix. A unitary cover has pockets connected by a spine strap. Each pocket receives one of the end pads of the unitary body. A number of straps on the cover serve to attach the cover and the unitary body to the limb of the patient.
The Holland device suffers from a number of shortcomings. The removable cover does not entirely enclose the deformable unitary body, leaving exposed portions of the unitary body including edges which can press into the skin and tissues of the patient. This requires that the foam matrix around the aluminum endoskeleton provide cushioning. The exposed unitary body comes into contact with the patient and therefore must be periodically washed and cleaned, since the splint is worn for extended periods of time, often several weeks. The straps used to secure the splint to the patient's limb are attached directly to the unitary body, and are separate from the cover. Removal and reinstallation of the straps is needed for washing, adding complexity to the use of the device and exposing the straps to possible misplacement and loss.
Improved deformable static orthoses are needed featuring greater comfort and ease of use and maintenance.